Agonistic and grooming behavior of captive crowned lemurs (Lemur coronatus) during the breeding season

Captive breeding of rare and endangered prosimians may be enhanced by an increased understanding of all aspects of their seasonal mating behavior. In this study, the agonistic and grooming behaior of captiveL. coronatus were studied during their annual breeding season. Between October and March, selected aspects of agonistic and grooming behavior of four male-female groups were recorded. Males initiated significantly more allogrooming than females. The frequency of this behavior pattern increased significantly in the weeks of estrus. Females performed significantly more agonistic behavior patterns than males. The mean frequency of agonistic interactions decreased significantly during the breeding season. In successfully reproducing groups males showed much less agonism towards females, than they did in unsuccessful groups. Inter-specific comparisons demonstrated that the patterns of agonistic interactions during the breeding season are very different among closely related species of lemurids. The conclusions drawn from this study are that captive breeding of crowned lemurs may be enhanced by keeping permanent multi-male, multi-female groups.     

Mating behavior of ring-tailed lemurs (Lemur catta) at Berenty,Madagascar

The mating behavior of ring-tailed lemurs at Berenty, Madagascar, was observed in April 1982. Although Troop A included five adult females, only two were observed to mate. The mating period covered two consecutive days, April 24 and 25. Each female was receptive for about 4 hr. Data from 47 copulations, of which 38 were with ejaculation, suggest that to be the first mating partner is of importance for male ring-tailed lemurs. Previously it has been suggested that male dominance is of little significance in determining mating partners. In this investigation it was observed that the second most dominant male MK was always the first mating partner. Only after several ejaculations and resultant fatigue did he lose possession of the female to lower ranking males, and the first ranking male was not seen to copulate with either female at any time. These results suggest that a male's mating success is partly, but not completely correlated with his dominance rank, and that other factors, including his length of residence in the group and female choice, also determine patterns of mating.     

Intermale affiliative behavior in ringtailed lemurs (Lemur catta) at the Beza-Mahafaly reserve, Madagascar

Intermale affiliative behavior was studied in three groups of naturally occurring ringtailed lemurs over a one-year period. The adult males in the sample exhibited affiliative behavior with all other males in their social groups; but affiliative behavior between some male-male dyads occurred markedly more often than between others. These dyads are called “preferred partnerships.” The formation of preferred partnerships did not appear to be influenced by male dominance rank or age-class. Furthermore, these partnerships were of a short-term nature, and none persisted throughout the entire study period. The following factors may explain the absence of rank or age effects, and the brevity of preferred partnerships: (1) frequent fluctuation in the male dominance hierarchy in each study group; (2) the fact that higher-ranking males may not offer specific benefits to lower-ranking males; and (3) the fact that male dispersal affected the male membership of each group over the 12-month study period. The focal males engaged in significantly more affiliative behavior during the lactation period compared with the other reproductive seasons. Migration partners may offer each other predator protection during the transfer process, and although males that transfer together do not engage in alliance or coalition behavior towards resident males, males transferring in pairs or threesomes are in a better position to spot and defend themselves against attack by resident males. Migration partners also provide social contact for each other while in the process of immigration.     

Male-female affiliative relationships in naturally occurring ringtailed lemurs (Lemur catta) at the Beza-Mahafaly Reserve,Madagascar

Affiliative behavior between adult male and female ringtailed lemurs was examined as part of a project concerning male affiliation with conspecifics of all age/sex classes. Males in three social groups were studied over a 12 month period. Male-female preferred partnerships existed, and were variable according to reproductive season. Dominance rank, age, or tenure of the male did not appear to affect either the number of partnerships or frequency of affiliative behaviors that males had with females. However, males residing in groups with fewer males exhibited both higher frequencies of affiliative interactions with females and were nearest neighbors to females more often than males living in a group containing more males. Females were found to be responsible for proximity maintenance of male-female dyads in the majority of cases. Neither reproductive season nor seasonal availability of food resources strongly affected the frequency of affiliative interactions between males and females, it is proposed that an important aspect of successful group membership for male ringtailed lemurs relates to the development of social relationships with adult females. Males can benefit from such relationships in terms of greater centrality to the spatial core of the group, which can result in enhanced predator protection, greater opportunities for social contact, and potentially greater access to estrous females. © 1996 Wiley-Liss, Inc.     

Diurnal behavior of Lemur mongoz at Ampijoroa, Madagascar.

Lemur mongoz was observed for 28 h between February and July in Ampijoroa, northwestern Madagascar. The animals were diurnal, with peaks of activity in mid-morning and late afternoon. This finding contrasts with other reports that L. mongoz at the same site and somewhat later in the year are nocturnal. Group size was three or four. L. mongoz associated with L. fulvus during group progression and feeding and when giving alarm responses to man. Vocal signals consist of a range of intergrading grunts and shrieks; olfactory signals of apparent scent marking with the anogenital region, forehead, and palms of the hands; visual signals of mainly unritualized body movements and postures. All of these signals are quite similar to signals of L. fulvus.     

Population and territory stability of the Lemur catta at Berenty, Madagascar.

Several Lemur catta troops at Berenty, Madagascar have been censused repeatedly since 1963. In 1972, the entire reserve was censused. A recensus in 1975 showed that although some minor changes have occurred in the number of animals in individual troops, the population of the reserve as a whole, the core areas of the lemurs' territories, and their home range boundaries have all remained stable ever since the first complete census 3 years earlier.     

Population ecology of the ring-tailed lemur, Lemur catta, and the white sifaka, Propithecus verreauxi verreauxi, at Berenty, Madagascar, 1981

The diurnal lemurs Propithecus verreauxi verreauxi and Lemur catta at Berenty in southern Madagascar, have been studied for the last 30 years. The August 1981 census indicates that the population size of L. catta remains stable at 150 adults but that P. v. verreauxi troops have become fragmented and scattered and the population is apparently increasing. Eight different vegetation types were classified within the reserve and their influence on the distribution of L. catta and P. v. verreauxi investigated. Behavioural data obtained shows the niche separation between these two, potentially competitive, sympatric lemurs.     

Effects of spatial proximity and alliances on dominance relations among female ring-tailed lemurs (Lemur catta) at Berenty Reserve, Madagascar

In the present study, we describe a change in the dominance rank of the top-ranking female in a wild troop of ring-tailed lemurs (Lemur catta) at Berenty Reserve, Madagascar. After the top-ranking female fell to the bottom-ranking position, she was able to outrank a low-ranking female with the support of her adult daughter or an unrelated high-ranking female. These results indicate that, as in cercopithecine monkeys such as macaques and baboons, close proximity and alliances influence dominance relations among adult females in a wild troop of ring-tailed lemurs.     

Adaptive and phylogenetic significance of ontogenetic sequences in Archaeolemur, subfossil lemur from Madagascar

Among the best known of recently extinct Malagasy lemurs is Archaeolemur, which is represented by many hundreds of specimens. The phylogenetic affinities of this taxon are unclear, especially in light of recent preliminary analysis of ancient DNA which does not support its previously accepted close relationship with the living Indridae. We examined the nearly complete skeletons of two adults and one juvenile and other less complete specimens to reconstruct aspects of the ontogeny of Archaeolemur. To compare the development of Archaeolemur to that of living strepsirrhines we collected data on Propithecus verreauxi, Eulemur fulvus, and Lemur catta. Additionally, because Archaeolemur exhibits some morphological convergences with distantly related papionins, we tested for convergence in the developmental patterns of Archaeolemur and Macaca fascicularis. Data include the status of tooth eruption, craniofacial sutural closure, and postcranial epiphyseal fusion, as well as linear measurements. We used discriminant function analysis and other tools to explore ontogenetic similarities and differences. The adaptive and phylogenetic significance of ontogenetic information is discussed. Our analysis shows that Archaeolemur displays a clear strepsirrhine pattern of development with only minor macaque convergences. Among the Strepsirrhini, Archaeolemur is slightly more similar developmentally to E. fulvus and L. catta than to P. verreauxi. Some of the distinctive features of the ontogeny of Archaeolemur may be related to diet, while others bear apparent testimony to a relatively rapid absolute pace of growth and development.     

The oestrous cycle of the brown lemur, Lemur fulvus.

Examination of vaginal smears and observations of the colour and tumescence of the genitalia and discharge of mucus of 9 brown lemurs indicated that the oestrous cycle lasted for 30 days and that cycles occurred between September and July. The timing of cycles of females housed in visual isolation differed from that of females able to see other lemurs, indicating that the oestrous cycle in this species can be influenced by different housing conditions.     

Vigilance behavior during the birth and lactation season in naturally occurring ring-tailed lemurs (Lemur catta) at the Beza-Mahafaly Reserve,Madagascar

I examined the vigilance behavior of adult males and females in two groups of ring-tailed lemurs(Lemur catta)during the birth and lactation season at the Beza-Mahafaly Reserve, southwestern Madagascar. I found no sex difference with respect to the rates of overall vigilance, rates of vigilance toward a potential predator or unfamiliar sound, or rates of vigilance toward conspecifics from other social groups, nor were there sex differences in the percentage of time spent vigilant in any of the above categories. Higher-ranking females were vigilant significantly more often toward predators or potential predators than lower-ranking females were. I detected no relationship between vigilance behavior and dominance rank among adult males. The alpha female in each group exhibited significantly more vigilance behavior than all other members of her group. It was predicted that males should exhibit more vigilance behavior than females do, particularly during the birth and lactation season, when predator pressure is high, if they are benefiting females in this respect. I discuss the results in the context of this prediction and in terms of how ring-tailed lemur males benefit females, and why they may be tolerated in social groups.     

Hunting,disturbance and roost persistence of bats in caves at Ankarana,northern Madagascar

Surveys and monitoring of 37 caves in and around the Ankarana Special Reserve, northern Madagascar, yielded evidence of hunting of bats and potential disturbance of bats by miners and tourists, and colony counts for several bat species of potential conservation concern. Colony size decreased by 95% and 14% for a colony of Hipposideros commersoni and a colony of Eidolon dupreanum, respectively, when recent evidence of hunting occurred at those colonies and those declines are probably attributable to hunting. Evidence of hunting occurred commonly at the roosts of those species and most commonly at the roosts of Rousettus madagascariensis. Hunting of pteropodids was associated with high vulnerability of roosts to hunters, little forest buffer between the cave and open savannah and the absence of tombs in the cave. Roost sites of the hunted species persisted for at least several years and this regularity may facilitate hunting. This work supports the ranking of E. dupreanum, R. madagascariensis and H. commersoni as species of conservation concern. Managers should consider the impact of tourist visits on bats and of increasing access to caves for tourism. Conservation efforts for the hunted species should also seek to protect vulnerable and unprotected cave roosts.     

Ecology,conservation, and phylogenetic position of the Madagascar Jacana Actophilornis albinucha

The Madagascar Jacana Actophilornis albinucha (Jacanidae) is an endemic shorebird found in the threatened wetlands of western Madagascar. This species is presumed to exhibit classical polyandry; however, few data are available to support that assumption. More generally, a lack of basic understanding of this species hinders conservation efforts. We conducted the most extensive study of the Madagascar Jacana to date, and report on its: 1) distribution, population size and density; 2) degree of sexual size dimorphism; and 3) phylogenetic position. The surveys were conducted at 54 lakes, between January and October in 2016. Madagascar Jacana were found at 22 lakes, and within these were distributed at a mean density of 3.5 ± 0.74 [SE] individuals per hectare of surveyed habitat. We estimate the global population size to be between 975 and 2 064 individuals, and habitat destruction appears to be the main threat to the species. Females were significantly larger than males, consistent with reports for other Jacanidae species. Using a mitochondrial DNA fragment, we expanded the Jacanidae genetic phylogeny, and confirmed that Madagascar Jacana is the sister species to the African Jacana Actophilornis africanus. Further studies are urgently needed to thoroughly re-assess the threat status and population trend of the Madagascar Jacana.     

Attacks on a wild infant ring-tailed lemur (Lemur catta) by immigrant males at Berenty, Madagascar: interpreting infanticide by males

An orphaned infant ring-tailed lemur (Lemur catta) was attacked persistently by immigrant males and disappeared with severe wounds at Berenty Reserve, Madagascar. Prior to the attacks, two troop members disappeared. On 20 November 1998, the only resident male in Troop C2B disappeared suddenly. After the disappearance, nine males from three neighboring troops approached, but only six males continued to shadow the troop. Of the females, the one lactating female attacked the males the most frequently. On 21 January 1999, the lactating female disappeared and her infant was orphaned. Subsequently, five attacks on the infant by immigrant males were observed for five consecutive days from January 23 to 27. The aggression was persistent and specifically targeted the infant, suggesting that the attacks were purposeful aggression, rather than redirected or accidental aggression. The primary attacker was the most dominant of the immigrant males, and mated with females in the next mating season.     

A comparison of salivary pH in sympatric wild lemurs (Lemur catta and Propithecus verreauxi) at Beza Mahafaly Special Reserve, Madagascar

Chemical deterioration of teeth is common among modern humans, and has been suggested for some extinct primates. Dental erosion caused by acidic foods may also obscure microwear signals of mechanical food properties. Ring-tailed lemurs at the Beza Mahafaly Special Reserve (BMSR), Madagascar, display frequent severe tooth wear and subsequent tooth loss. In contrast, sympatric Verreaux's sifaka display far less tooth wear and infrequent tooth loss, despite both species regularly consuming acidic tamarind fruit. We investigated the potential impact of dietary acidity on tooth wear, collecting data on salivary pH from both species, as well as salivary pH from ring-tailed lemurs at Tsimanampesotse National Park, Madagascar. We also collected salivary pH data from ring-tailed lemurs at the Indianapolis Zoo, none of which had eaten for at least 12 hr before data collection. Mean salivary pH for the BMSR ring-tailed lemurs (8.098, n=41, SD=0.550) was significantly more alkaline than Verreaux's sifaka (7.481, n=26, SD=0.458). The mean salivary pH of BMSR (8.098) and Tsimanampesotse (8.080, n=25, SD=0.746) ring-tailed lemurs did not differ significantly. Salivary pH for the Indianapolis Zoo sample (8.125, n=16, SD=0.289) did not differ significantly from either the BMSR or Tsimanampesotse ring-tailed lemurs, but was significantly more alkaline than the BMSR Verreaux's sifaka sample. Regardless of the time between feeding and collection of pH data (from several minutes to nearly 1 hr), salivary pH for each wild lemur was above the "critical" pH of 5.5, below which enamel demineralization occurs. Thus, the high pH of lemur saliva suggests a strong buffering capacity, indicating the impact of acidic foods on dental wear is short-lived, likely having a limited effect. However, tannins in tamarind fruit may increase friction between teeth, thereby increasing attrition and wear in lemurs. These data also suggest that salivary pH varies between lemur species, corresponding to broad dietary categories.     

Assessment of organochlorine pesticides and metals in ring‐tailed lemurs (Lemur catta) at Beza Mahafaly Special Reserve,Madagascar

Like most of Madagascar's endemic primates, ring‐tailed lemurs (Lemur catta) face a number of threats to their survival. Although habitat loss is of greatest concern, other anthropogenic factors including environmental contamination may also affect lemur health and survival. In this study, we examined ring‐tailed lemurs from the Beza Mahafaly Special Reserve (BMSR), southern Madagascar for exposure to organochlorine (OC) pesticides and metals and examined differences in contaminant concentrations between sexes and among age groups, troops, and habitats. A total of 14 pesticides and 13 metals was detected in lemur blood (24 individuals) and hair (65 individuals) samples, respectively. p,p′‐DDT, heptachlor, aldrin, heptachlor epoxide, endrin aldehyde, and endrin were among the most prevalent pesticides detected. Surprisingly, the persistent metabolite of p,p′‐DDT, p,p′‐DDE, was not detected. The most commonly detected metals were aluminum, zinc, boron, phosphorus, silicon, and copper, whereas metals considered more hazardous to wildlife (e.g. arsenic, cadmium, lead, selenium, vanadium) were not found above detection limits. Overall, concentrations of OC pesticides and metals were low and similar to those considered to be background concentrations in other studies examining the ecotoxicology of wild mammals. Few inter‐sex, ‐age, ‐troop, and ‐habitat differences in contaminant concentrations were observed, suggesting a uniform distribution of contaminants within the reserve. Several statistically significant relationships between lemur body size and contaminant concentrations were observed, but owing to the lack of supportive data regarding contaminant exposure in wild primates, the biological significance of these findings remains uncertain. Results of this study document exposure of ring‐tailed lemurs at BMSR to multiple OC pesticides and metals and provide essential baseline data for future health and toxicological evaluations of lemurs and other wild primates, especially those in regions with expanding agricultural and mining operations. Am. J. Primatol. 71:998–1010, 2009. © 2009 Wiley‐Liss, Inc.     

Coat condition of ringtailed lemurs,Lemur catta at Berenty Reserve,Madagascar: I. differences by age,sex, density and tourism, 1996–2006

An index of coat condition can be a non‐invasive tool for tracking health and stress at population level. Coat condition in ringtailed lemurs, Lemur catta, was recorded during September–November birth seasons of 1996, 1997, 1999, and 2001–2006 at Berenty Reserve, Madagascar. Condition was scored on a scale from 0: full, fluffy coat with guard hairs present, to 5: half or more of body hairless. Adult males did not differ overall from adult females. Coats were worse in adults than in 2‐year‐old subadults; 1‐year‐old juveniles were intermediate. Mothers and adult males lost coat condition as the season progressed: non‐mother females maintained condition. Years 1999–2002 scored better coats than either 1996–1997 or 2003–2006. Lemurs in high population density areas had worse coats than in natural forest, but tourist presence had less effect than density. Monitoring coat condition in an apparently healthy population reveals differences between population segments, and in a forest fragment with limited immigration or emigration it can track progressive changes, correcting impressions of progressive improvement or degradation over time. Above all it gives a baseline for response to climate changes or eventual pathology. Am. J. Primatol. 71:191–198, 2009. © 2008 Wiley‐Liss, Inc.     

Coat condition of ringtailed lemurs,Lemur catta,at Berenty Reserve,Madagascar: II. Coat and tail alopecia associated with Leucaena leucocepahala, 2001–2006

Fur condition in wild ringtailed lemurs, Lemur catta, was recorded during September–November birth seasons 2001–2006 at Berenty Reserve, Madagascar. Body coat condition was scored on a scale from BS 0: full, smooth coat with guard hairs, to BS5: half or more of back and limbs hairless. Tail condition was scored from TS 0: full, to TS 5: half or more hairless. Where troop core areas included stands of Leucaena leucocephala, alopecia was dramatically more frequent than in similar areas without leucaena, including many animals with score BS5 or TS5, “bald lemur syndrome.” Female coats were worse than males,' possibly related to female dominance and access to this preferred food. Tails in non‐leucaena‐feeding females tend to remain full, even if coats deteriorate, but with leucaena‐feeding female tails are highly correlated with coat condition and equally bare. Coat and tail condition in L. catta reflected not only the dietary toxin but individual differences as well as differences between adjacent troops that may result from territorially mediated access to the environment. Leucaena contains the non‐protein amino acid mimosine, a known cause of alopecia, wasting, and organ damage in livestock, although the effects are usually reversible. This is the first case of its effect in wildlife. Leucaena is an agroforestry tree introduced throughout the tropics. In high dietary concentrations leucaena might potentially affect any browsing mammal. Am. J. Primatol. 71:199–205, 2009. © 2008 Wiley‐Liss, Inc.